Halyards comprise the running rigging used to raise and lower the sails on sailing craft. The halyard extends from the boat deck to the head of the mast where it is trained around a sheave. One end of the halyard is secured to the sail, the opposite free end often extends under a turning block at the foot of the mast and passes through a halyard stopper anchored to the boat deck or superstructure. The stopper is designed so that the free end of the halyard can be pulled freely in a direction that will raise the sail. However, the stopper prevents travel of the halyard in the opposite direction that will lower the sail, at least until the stopper has been intentionally disengaged from the halyard when it is actually desired to lower the sail.
There are several different varieties of halyard stopper in existence today. The simplest one is basically a jam cleat which has a fixed base formed with teeth and an arcuate cam also formed with teeth pivotally positioned opposite the fixed surface. The curvature of the cam and the inclination of their teeth are such that, when a line is threaded between them, the line can be pulled in one direction that tends to swing the cam away from the base. However, when the line is pulled in the opposite direction, it is engaged by the teeth with the result that the cam is pivoted ever more tightly toward the base, thereby jamming the line. The stopper can be released to disengage the line by manually pivoting the cam away from the base.
The main disadvantage of that type of fitting for use as a halyard stopper stems from the fact that a halyard is often under tremendous tension, on the order of 3,000 to 4,000 pounds. Therefore, once that line is pulled in to raise a sail and is released, the tension on the line in the opposite direction jams the cam toward the base to such an extent that it is very difficult to swing the cam away from the base in opposition to that large force. It is easier to release the stopper if the line is pulled in at the same time. However, that often requires two pairs of hands.
Attempts have been made to design stoppers which can be released easily by one hand even though the halyards which they control are under very high tension. One type of prior stopper of which we are aware comprises a jam cleat whose cam member can be pivoted relative to the base by way of an eccentric. When a line is passed between the cam and the base, the line can be pulled in one direction which tends to pivot the cam away from the base. However, tension on the line in the opposite direction causes the cam to pivot toward the base and jam the line. This type of stopper is released by rotating the eccentric which essentially swings the cam pivot away from the base so that the line is free to move in both directions. That conventional stopper is overly expensive. This is mainly because its cam requires a large socket for the eccentric. Therefore, it has to be a cast or machined part; it cannot be extruded.
Another prior halyard stopper employs a toothed base having a curved toothed cam surface pivotally mounted above the base. A relatively complex lever arrangement operates the cam. That prior stopper is disadvantaged in that, when the tensile force on the line is intermittent, its cam chatters, i.e. pivots rapidly toward and away from the base in such a way as to permit the line to pay out intermittently. Moreover, any given size of that type halyard stopper can only handle a given size line. In other words, if it is desired to change the diameter of the running rigging on a particular boat, it is necessary to change the size of that type stopper correspondingly. Another disadvantage of that prior halyard stopper is that the position of its cam is such as to interfere with the threading of the leading end of the line into the stopper. Also, when the halyard is pulled in, the stopper tends to chafe and abrade the line thereby shortening the life of the line.
Still another type of prior halyard stopper employs a fixed toothed base and a spring-loaded, over-center toothed cam mounted on a pivot arm which is swung down against the base by a lever arm. This type of stopper is also difficult to load in that the spring-loaded cam inhibits passage of the leading end of the line between the cam and the base. For the same reason, the stopper chafes the line when the line is pulled in. Still further, the lever arm of that type stopper is located at the bottom of the fitting and projects out therefrom. Consequently, moving lines in the vicinity of the stopper tend to catch and release the arm, thereby inadvertently releasing the halyard. That prior stopper also retains only certain size lines. More particularly, when its lever arm is in one orientation, the stopper will jam one size line. However, the lever arm can be flipped over so as to present a different orientation enabling the stopper to jam a second line of different size.
In use, when the handle of that type halyard stopper is in its locked position, there is no ready movement of the halyard in either direction. One can pull in on the halyard by applying a relatively high tensile force to the halyard. This causes the over-center cam to compress the engaged segment of the halyard to the extent that the cam swings away from the base and releases the halyard. However, the required force is quite large. In order to reduce the amount of force required to pull in on the halyard, one may partially release the stopper. In that event, however, the halyard is free to move in both directions, which is undesirable.
Aside from the simple jam cleat, the prior halyard stoppers are quite complicated and incorporate several parts which are relatively difficult to fabricate. Accordingly, the prior fittings are quite expensive. Also, some are quite wide so that they occupy a relatively large amount of space when stacked side by side as they often are in use.